The invention relates to a catheter having inflatable means for dilation of the prostate urethra, and to a method for the treatment of benign prostatic hyperplasia.
Balloon catheters are widely used for dilation of undesirable tissue in body vessels. For instance, U.S. Pat. No. 4,636,195 discloses removal of constrictions caused by deposition of plaque in arteries by a balloon catheter. The disclosed catheter has two smaller ring balloons spaced around a central dilation balloon. The smaller ring balloons provide a chamber around a body of plaque, and help to hold the catheter body in place. Other multiple balloon catheters are disclosed in U.S. Pat. Nos. 4,573,966 and 4,610,662, both assigned to Schneider Medintag A.G. The two balloons of these catheters are placed in a vascular passageway to seal off a constricted area, and dissolving fluid is supplied to the enclosed area to dissolve the constrictive tissue.
Treatment of obstructive tissue in the prostate urethra with a balloon catheter is disclosed in Klein U.S. Pat. No. 4,660,560. Klein describes a catheter having a Foley balloon for anchoring the catheter by inflation within the bladder, and an annular balloon for dilation of the prostate urethra. Klein attains proper location of the annular balloon by introducing a cystoscope into the prostate urethra. The operation of the cystoscope to determine the location of the prostate urethra with respect to the bladder neck is cumbersome, and can be avoided by the invention as described below.